The Center for Alternatives to Animal Testing is an academic center affiliated with the Division of Toxicological Sciences in the Department of Environmental Health Sciences of the Johns Hopkins University Bloomberg School of Public Health.

 

Johns Hopkins School of Public Health

Commemorative Booklet for CAAT 20th Anniversary Symposium

Development of Precision-Cut Tissue Slices as an In Vitro Model for Pharmacological, Toxicological, and Biotransformation Studies

A. Jay Gandolfi and Klaus Brendel
University of Arizona, Tuscon

Organ culture has long been hampered by inconsistency and irregular thickness of the tissue sections and culture techniques that did not adequately maintain tissue viability. CAAT provided, in part, the initial funding that led to the successful development of an alternative technique to overcome these difficulties.

Using our own improved versions of Krumdieck's apparatus, we were able to take cores of animal liver or kidney tissue and prepare many very reproducible (< 5% thickness variation), thin (250 microns) slices. These slices could be maintained in organ culture due to the ease of diffusion of gases, nutrients, and wastes into and out of the slices.

To facilitate this exchanges of nutrients, gases, and wastes we developed a tissue culture system that incorporated the partial submersion concept of organ culture along with the dynamic mixing of roller culture. When prepared and incubated in this fashion, the tissue slices maintain their viability, tissue-specific characteristics, and cellular architecture for 3-5 days. The slices proved useful for pharmacological (hormone, growth factor, drug) studies, site-specific toxicological studies unique to the tissue, and biotransformation studies.

Since virtually any isolated tissue could be cored and then sliced, the technique spread to numerous other tissues (e.g. heart, lung, spleen, brain) and species (e.g. rat, mouse, guinea pig, dog, fish). The technique was particularly useful with human tissue (liver, kidney, lung), thus eliminating the need to extrapolate laboratory animal results to humans.

Overall, our tissue slices offer an in vitro system that retains many of the unique characteristics of a tissue and is applicable to numerous tissues and species, including human tissues. The CAAT funding was quickly leveraged into nine years of NIH funding for further development of this technology. We recently received an NIH Small Business Technology Transfer grant for developing slice technology in transgenic animals containing fluorescent reporter genes. Slices from these animals will "light up" when exposed to toxicants. We are in the process of developing rapid toxicity screens for numerous tissues using these animals.